// Settings
var showItems = 12; // number of items to show

// Globals
var listPos = 0;
	
function initPlist(){	
	
	nextBut = document.getElementById("nextButton");
	prevBut = document.getElementById("prevButton");
	
	elements = document.getElementById("pfolio_list");
	dtItems = elements.getElementsByTagName("dt");
	ddItems = elements.getElementsByTagName("dd"); 
	numItems = dtItems.length;
	maxPos = Math.floor(numItems / showItems);
	
	if(numItems > showItems) document.getElementById("butNav").style.display = "block";
	
	// hide all items
	for (i=0;i<numItems;i++){
		dtItems[i].style.display = "none";
		ddItems[i].style.display = "none";
	}
	
	// show first panel of items
	for (i=0;i<showItems;i++){
		if(dtItems[i]) dtItems[i].style.display = "block";
		if(ddItems[i]) ddItems[i].style.display = "block";
	}
	
	nextBut.style.display = "inline";
	
}


function nextList(){
	if(listPos < maxPos){
		position = listPos*showItems;
		
		// hide previous
		for (i=position;i<(position+showItems);i++){
			if(dtItems[i]) dtItems[i].style.display = "none";
			if(ddItems[i]) ddItems[i].style.display = "none";
		}
		
		listPos ++;
		position = listPos*showItems;
		
		// show next
		for (i=position;i<(position+showItems);i++){
			if(dtItems[i]) dtItems[i].style.display = "block";
			if(ddItems[i]) ddItems[i].style.display = "block";
		}
		
		prevBut.style.display = "inline";
		if(!(listPos < maxPos)) nextBut.style.display = "none";
		
	}	
	
}

function prevList(){
	if(listPos > 0){
		position = listPos*showItems;
		
		// hide previous
		for (i=position;i<(position+showItems);i++){
			if(dtItems[i]) dtItems[i].style.display = "none";
			if(ddItems[i]) ddItems[i].style.display = "none";
		}
		
		listPos --;
		position = listPos*showItems;
		
		// show next
		for (i=position;i<(position+showItems);i++){
			if(dtItems[i]) dtItems[i].style.display = "block";
			if(ddItems[i]) ddItems[i].style.display = "block";
		}
		
		nextBut.style.display = "inline";
		if(!(listPos > 0)) prevBut.style.display = "none";
		
	}
	
}